One of the existing procedures to remove brain tumors at the skull base is endonasal neurosurgery. This surgery uses the nose and sinuses as a pathway to access the base of the skull. Instruments are used to erode away bone to create a hole in the back of the sinuses through the sphenoid sinus and in proximity to the sella turcica; this area is referred to as the skull base. A skull base defect is any opening in the bony layer, filled with tissue or not, between the brain cavity and any of the sinuses. This surgery is done primarily to remove tumors on or near the pituitary gland. However there are cases where the patient has preexisting holes in the bone between the brain cavity and the sinuses. In general this embodiment is used to seal all holes between the sinuses and brain cavity regardless of the manner in which the hole is made. The most common manner and thus the most thoroughly discussed are holes made by surgeons for removal of tumors.
The most difficult stage of endonasal neurosurgery is closing the hole in the skull. The current method of sealing a hole in the skull base involves inserting fat, often harvested from the patient's belly button, in to the hole. This is followed by packing multiple pieces of biocompatible foam into the hole and sealing it with glue; often fibrin glue.
Endonasal neurosurgery has a mortality rate of less than 1% but a morbidity rate of 12%. The majority of morbidity (9%) is the result of skull base seals failing. It is important to note that the traditional closing procedure makes a plug to mend the tissue layer but does nothing to replace the bone that is removed to enter the skull. The patient has a permanent hole in their skull which contributes to long term morbidity. Complications include but not limited to cerebral spinal fluid leakage and meningitis.
US Published Patent Application 2007/0270841 presents an implantable device for sealing the sphenoid sinus or sella turcica. This publication does not describe any use of a compounded that sets to a hardened state to seal a defect. This publication does not describe a device to assist in the placement of a seal. This publication does not describe a seal made of a plurality of materials.
“Sellar Repair in Endoscopic Endonasal Transsphenoidal Surgery: Results of 170 Cases”, published in Neurosurgery 51:1365-1372 by Cappabianca et. al. in 2002 describes the most common method used by those skilled in the art for sealing a skull base defects. This publication does not describe the use of a compound that sets to a hardened state to seal a defect. This publication does not describe a device other than commonly available surgical tools for tissue resection and manipulation to assist in the placement of a seal.